Battery charger



FIG. 1 is perspective view of a battery charger showing my new design;

FIG. 2 is a right view thereof;

FIG. 3 is a left view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a top view; and,

FIG. 7 is a bottom view thereof.

The broken lines in the figures depict portions of the article which form no part of the claimed design. 

CLAIM The ornamental design for a battery charger, as shown and described. 